Fluid logic pack



United States Patent Robert A. van Berkum 177 Fernwood Road, ChagrinFalls, Ohio [72} inventor 44022 21 1 Appl. No. 796,397 221 Filed Feb. 4,1969 451 Patented Dec. 15, 1970 [32] Priority Feb. 23, 1968 [33] Canada[31] No. 013,220

[54] FLUID LOGIC PACK 12 Claims, 16 Drawing Figs.

[52] U.S.Cl 137/8l.5,

137/608 51 1 Int. Cl FlSc 5/00 [50] FieldofSearch 137/8l.5;

[56] References Cited UNITED STATES PATENTS 3,461,900 8/1969 Dexter eta1. 137/81.5

3,465,772 /1969 Monge et a1. l37/81.5 3,465,774 9/1969 Kautz et a1137/608 3,473,568 10/1969 Pfitzner et al 137/81.5X

Primary Examiner-Wi1liam R. Cline Attorney-Graham & Baker ABSTRACT: Afluidic logic circuit assembly comprising a plurality of independentlogic elements stacked together to provide a fluid supply conduitthrough the stack, conduit input and output passages in each of theelements brought to one face of the stack and circuit plates assembledagainst the one face to provide input and output connections andinterconnections to the elements and to the pack. Venting passages forthe elements are preferably brought to another face of the stackseparate from that for the circuit plates. The fluidic devices may beformed directly in the elements or alternatively may be inserted intoreceptive pockets in wafers forming the stack. A booster arrangement forimproving output of any elements from which there is considerablefan-out is also described vention;

FLUID LOGIC PACK This invention relates to a fluidic logic circuitassembly and has particular reference to an integrated assembly whichcan be. built up from standard parts, and whichlends itself tomodification in a simple manner. e i

Fluidic logic circuits are becoming increasingly prevalent particularlyfor the control of items which require movements suitably executedbyhydraulic or fluid actuators. Examples of these are boiler controlsystems, hydraulic machinery, lathes, earth-working equipment, spacevehicles, stable platforms and indeedmany'items which conventionally areoperated by electronic circuitry. Fluid circuitry offers the advantageof being particularly reliable less subject to shockand damage,impervious to nuclear radiation damage and' beingable to be run quiteindependently of electrical supplies; t i The type of circuit andapparatus with which fluidics can be. used isdisclosed in my copendingUS. Pat. application, Ser, No. 674,903 filed Oct. 12, 1967, nowabandoned.

While partly integrated fluidiccircuits have beendescribed in the past,they have in general tended 'to be of, the bread board type requiringmany interconnecting-pipes similar in many ways to the wired type ofelectronic circuit. This scheme while effective for some purposesmakes-it difficult in the space available to include as'rnany activeunits as may be desired and a balance between volume occupied, speed ofoperation, and the number of circuit components has to be made.

' In practicing the present invention, circuitry more akin to theintegrated type-of electronic circuithas been made possible resulting ina compact fast operating and economic unit.

More particularly in accordance with the'invention there is providedafluidic logic assembly pack which comprises a plurality of independentlogic elements said elements being stacked and providing a continuousfluid supply conduit through said stack input and output passages ineach of said elementsbrought to a single face of each said element andproviding a multiplicity of ports on one face .of said stack, circuitplates assembled against said one face of said stack and providinginterconnecting passages between selected ones of said ports, means forfastening said stack and said plates,

means for supplying fluidfto said conduit andmeans for connecting fluidinput signals to and forfrece'iving output fluid signals from saidplates. The apparatus may also include venting passages for each elementwhich preferably are discharged to the opposite face of the stackoccupied by the circuit plates. Alternatively the elements may be madeup 'of discrete units inserted into receptive pockets in' wafers formingthe stack. Fluid booster means may be provided by leading supply fluidtothose passages from which there. is considerable fan-out" andelectrical input and outputs can be provided by the use of electricallyoperated fluid valve inputs and fluid operated electric switch outputs.

A description of specific embodiments of theinvention now follows havingreference to the accompanying drawings in which:

FIG. 1 shows a side partly sectional view'. of a typical integratedfluidic circuit constructed in accordance with the in- FIG. 2 showsarearview; 1

FIG. 3 shows a top view of the device of FIG. 1;

' FIG. 4 is a plan view of an active element assembly wafer;

FIG. 4a, is a partial section of FIG. 4 along the line IVa-IVa; FIG. 5is a reverse view of the wafer of FIG; 4;

FIG. 6 shows a plan view of an alternative active element wafer intendedto take insert units; I J

FIG. 7 shows a vent plate-for use in conjunction with the apparatus ofFIG. 6, and v I FIG. 8 a back up plate for use with the vent plate ofFIG. 7;

FIG. 9 is an inner circuit plate for supply of signals to and receivingsignals from the upper edges ofthewafers of FIGS. 4 and 6;

FIG. 10 is an outer circuit plate operating in conjunction with thecircuit plate of FIG. 9;

FIG. 11 shows a supply manifold'forintroducing operating fluid for thewafer stack;

FIG. 12 is a partly diagrammatic section of the assembled pack showingsuitable apparatus for feeding electrical signals to and from thefluidic logic circuit;

FIG. 13 shows in greater detail asuitablesolenoid assembly for use inthe assembly of FIG. 12;

FIG. 14 shows a suitable electrical output circuit for use in theassembly of FIG. 12; and 1 FIG. 15 is a schematic diagram of a pair ofOR elements connected as a bistable.

One assembly constructed in accordance with the invention is shown inFIGS. 1, 2 and 3. This comprises a stack 4 of wafers carrying activelogic elements'fastened to a source manifold header 9 and an end blockI0. Bolts 11 pass through these items and can be drawn up tightbysuitable means such as nuts 12. This first assembled subunit is thenplaced as a sandwich between the circuit plate assembly 8 faced by acapping plate 1 which contacts face 6 of .the stack 4 and a vent backupplate 7. Bolts 3 pass through the assembly from the capping plate 1 tothe backup plate 7' drawing the whole assembly into a secured unit.Details of the wafer stack 4 will be given later with reference to FIGS.4, 5 and 6.

The circuit plate assembly 8 consists of a plurality of circuit plates,exemplified as 15, 16, and 17 (though more may be provided if needed)separated from one another and from the clamping plate 1 by gaskets 19,20 and 21; The plate assembly 8 is further provided with input/outputconnections 25, at the rear of the unit and, if desired, alternativefront input/outputs, at 26 in block 28 secured to assembly 8, andconnected into the circuit plate assembly 8 by passages formed in theblock 28'.

- Fluid for supplying the sources of the fluidic, elements in the waferstack 4 is introduced at 30 in header 9 Referring now to FIGS. 4 and 5,a typical wafer plate 32 forming one member of the stack 4 has four ORunits engraved into the surface of the wafer. Holes 34 are formed in thewafer which when assembled with 'other wafers form continuous conduitstraversing the stack 4'and connecting with the manifold 9. The manifold9 is-shown in detail in FIG. 11, the passages formed by the holes 34connect ing with groove Fluid, is thus available in the conduit formedby holes 34 and can bleed off at the source entrance 35 of a typical ORunit 36 when (in the absenceof other inputs) an output will appear inlimb 37'at port 37' on edge 6. Venting relief is given to limb 37 athole 38 which allows excess fluid to vent through the wafer 32 where itcollects in cut out vent cavity 39 to bleed away through vent plate 7 atedge 5. Inputs to the fluidic unit 36 can be fed in at ports 40 or 41and are vented beyond the neck 43 of the unit at hole 42 againinto'cavity 39. In the presence of an input at 40 or 41 the flow throughthe neck 43 shifts and appears in limb 45 instead of limb 37 providingan output at port 45'. Venting is again provided at hole 46 to allowexcess fluid to pass into cavity 39.

Reference to FIG. 6 shows an alternative form 50 for one of the wafersforming a stack 4. Source fluid passes through the stack by way .of aconduit formed by holes 5-1 in each wafer. A plurality of recesses 52are formed in each wafer into which a respective active fluidic elementmay be inserted. Such elements are available commercially, forinstance'from Aviation Electric Ltd., Montreal, Canada If a typical'ORunit were inserted in the wafer 50 of FIG. 6, inputs would be providedat ports 53 and 54 and outputs would be available at ports 55 and 56.Venting for the inputs can occur through hole 58 and for the outputs at59 and 60. respectively. In this instance a vent plate 71 (FIG. 7) isprovided behind each wafer 50 so that vent holes 58, 59 and 60 connectwith the vent passage of the vent plate 71 bleeding away at the edge 72(aligned with edge 5) into the exhaust plate 7 (FIG. 3).

It can now be seen that connection is made to the circuit plate assembly8 by the engagement of edge 6 of the stack 4 against the assembly. Theinput and output 'ports at the edge 6 of each wafer are made to matewith holes such as 69 in plate 15 (See FIG. 1 and FIG. 9) and fluidicconnections are made between these holes and selected other holes in theplate 15 by engravings formed in the plate. Where crossovers occur,connection between the respective holes in plate can be made by formingengravings in plate 16 whose holes line up precisely with those ofplates 15. If double crossovers are required additional engravings canbe made in plate 17 corresponding to the holes for plates 15 and 16. Thegaskets 19, 20 and 21 pierced in an exactly similar pattern of holes tothe plates 15 and 16 prevent any passage of fluid except in the axialdirections of the respective holes and throughthe engravings. Thisassembly 8 therefore carries out the connection between the elements instack 4 to the input/output terminal faces 25 and 26. All holes areblind-ended by the clamping plate 1 or the plate 17 except whereconnectionmay be required to the exterior for input or output. Ifadditional circuit plates are 1 necessary in any particular constructionthey can be introduced under the plate 1 or 17 with suitable gaskets andwill be made with the same pattern of holes as the other plates and beengraved for those interconnections desired to be made.

The bolts 3 (FIG. 1) pass through the' holes 3' of FIGS. 9 and Thestructure of the stack 4 differs slightly depending upon 'whether it isconstructed of wafers of the form of 32 FIGS. 4 and 5) or of wafers(FIG. 6). When using wafers 32 each will be separated from the next by aflat spacer plate pierced with holes corresponding to the holes 44 ineach wafer 32 for the bolts 11 (FIG. I), and also with holescorresponding to 34 'of wafer 32 to define the source fluid conduits.The spacer plate thus confines the fluidic flow in each element to itsdesigned passages.

When a wafer of the type shown in FIG. 6 at 50 is employed,

'each wafer is separated from the next by a vent plate 71 of FIG. 7.This includes holes 51' corresponding to holes 51 in the wafer 50 assource fluid conduits, and also fastening holes '80" corresponding toholes 80 of waferv 50 to accommodate fastening bolts corresponding tothe bolts 11. The manifold 9 also includes holes 11' for these bolts(FIG. 11). Since the grooves 70 of vent plate 71 do not pass rightthrough the plate 71 both venting for the holes 58,, 59 and 60 andcapping of the adjacent wafer 50 to confine the fluidic flow in thatelement to the designated passages is provided. That end of the stack 4employing wafer 50 which is not adjacent to the header 9 has a blindending plate (which can replace end block 10 of FIG. 1) and caps off thesource fluid conduits formed by holes 51 and 51. The modification withthe blind end plate is employed when front input/output terminals arenot required. The stack 4 includes spacer places (not shown) betweencertain adjacent wafers which include grooves for allowing the bolts 3to 'pass across the stack. These plates also have suitably defined-holes to extend the source fluid conduits through them. 5 Input andoutput connections to the circuit plate assembly 8 -can be made bycarrying the circuit passages to regions such as 76 and 77 of FIG. 9(which connect with the holes 76' and 77' in the circuit plate 17 ofFIG. 10). The regions 76 and 77 can then be connected with inputs andoutputs 25 (FIG. 1). ---Similarly by taking the circuit passages to theregions 78 and 79 (corresponding to holes 78' and 79') inputs andoutputs at if 26 can be made available if needed. In a prototypeembodithem it was found desirable to introduce all inputs to regions 76and 77 through the capping plate I and take outputs directly from thecircuit through the capping plate 1. This ar- 'rangement is describedlater with respect to FIGS. 12, I3 and i 1 l4.

The face 67 of back up plate 7 FIGS. 1 and 8) butts against the edge 69of exhaust plate 71 (FIG. 7) so that grooves 68 receive vented fluidfrom passages 70 which in turn receive fluid from holes 58, 59 and 60(FIG. 6). Alternatively, when {used with'a stack 4 of wafers 32 (FIG. 4)exhaust plates 71 are absent and the grooves 68 then receive ventedfluid directly from cavities 39. The holes 3" (FIG. 8) receive the bolts3 (FIG. 1). Holes 75 lead the fluid from grooves 68 to be {deliveredinto a discharge conduit. This would particularly be required if thefluid ,'used were not expendible and were i=operating in aclosedc'yc'le.

It will be understood that with certain circuit elements it may be foundsatisfactory to vent to the circuit plate assembly 8 rather than to aseparate vent space and this can be provided by bringing the ventsthrough passages to ports on edge 6.

With reference to FIG. 12 and 13 inputs instead of passing through 25(FIG. 1) may be provided by a solenoid operated plunger such as from amanifold 111 connected to the supply header 9 by passage 112. Theplunger seals against gasket 109. When an electrical input at leads 113is provided to solenoid 114, plunger 110 is raised and-fluid passes fromthe manifold 111, via passage 115 in gasket 109. to the 0on nectinginput passage 117 formed in the clamping plate 1. The fluid then feedsby the means-already described through the circuit plate assembly 8.

When employing the input system just described it may also be useful totake outputs from the clamping plate I through passages 120. and 121connecting with the circuit plate assembly 8 into, for instance (FIG.14), a volume chamber 122 connected to a bellows 123 which can operate alimited movement switch 124 and provide an output at leads 125. Asexemplified in FIG. 14, if desired the passage 121 can be resistive byproviding orifice plate shaping at 131 or by restricted passage 120.Volume chamber 122 can provide capacitive action in conjunction withthis resistance. When using this input and output system the circuitplates, except plate 15, can include output holes A (See FIG. 10) offsetfrom the grid pattern described heretofor which mate with outputpassages in the capping plate 1. Air supply passage 112 for the solenoidheader 111 is shown in FIGS. 9 and 10, and threaded holes B used in theprototype for clamping the bellows assemblies to the capping plate 1 areshown in FIG.. 10. It can thus be seen that the invention permits thedesign of virtually every type of possible interconnection which mightbe required between any fluidic element in any of the wafers 32 or 50.Each circuit plate may be. made identically with the others, initiallyby providing ports at each one of the positions at which an input oroutput may be present on a wafer, and the interconnections between theseports then subsequently made to suit the particular circuit operationdesired, additional holes may be formed in the plates to allow otherconnections, not directly to an active element.

It is clear that this logic circuit pack can be modified in many ways asdetermined by the particular operations needed. Fewer wafers could beincluded by merely providing dummy spacer sections which are pierced toallow the source fluid to pass to the wafers that are active. The numberof circuit plates can be altered, as required by the total circuitfunction, because they are of standard format. The stack 4 can also bemade shorter by merely providing the number of active element wafersrequired and then capping off the stack. Although the circuit plateswill overhand the stack since they are a standard format there will beno interference with the circuit function because the holes in the platewhich would correspond with the ports in the absent active elements aremerely not connected in circuit. Additional elements can be addedlaterwhen new circuit plates can be made up, or the existing onesmodified,.to include the new elements.

It is an advantage to ventto-the surface opposite from that in which thecircuit functions occur and by providing a manifold collection system,the fluidic units can be used with any type of fluid whether in a closedor open cycle. It should also be understood that the stack 4 may containa mixture of different types of active fluidic elements thus waferscontaining bistable elements may be inserted in the stack along withwafers containing OR and memory and amplifier elements, etc. because allwafers in the stack are made to a standard format compatible with thebasic grid pattern of holes in the circuit plate fassembly 8. The schemeof providing for plug-in.

fluidic elements enables conventionally available types to be used,evenfor those in. which venting may occur on the same face as the inputsand the outputs. Crossovers of venting and input and output channels canreadily be provided, even though many fluidiccircuits may require avariety of elements.

such as AND, OR and bistable devices. If desired, bistables can beavoided for instance by interconnection of two ORs in known manner,(FIG. This in general, has been found to be more stable and less subjectto bounce or faulty operation due to system noise than the standardsingle fluidic flip-flop unit. Separate triggering inputs are fed in at140 and 141 and outputs are available at 142 and 143.

A booster system can be included by providing an additional flow ofsupply fluid to those ports of the circuit where flow or pressure isinsufficient for proper operation. This system is particularlysatisfactory in a circuit where the output in one limb of an element isrequired to feed several further units. In such a fan-out additionalfluid can be bled into the limb 134 (FIG. 4) by making a connectionshown by the engraved passage 135. Since ample additional fluid isavailable at the conduit formed by the series of holes 34, effectiveboosting results. By control of the size of passage 135 the avoidance ofinsufficient pressure to produce an output at 136 except when inputsoccur at 137 or 138 can be achieved. In cases where it is undesirable tomodify the fluidic element itself, the booster passage can be formed inthe circuit plate assembly 8. Suitably a passage having booster fluidfrom the manifold 9 (FIG. 1 and 11) can be run across the plate assembly8, and can be bled from there to any passage or port requiring a boost.

I claim: 1. A fluidic logic assembly pack which comprises a plurality ofindependent fluidic logic elements, said elements being stacked andhaving means providing a continuous fluid supply conduit through saidstack, input and output passages in each of said elements, said inputand output passages being brought to a single face of each said elementforming ports therein, said single faces being aligned to provide amultiplicity of ports on one face of said stack, circuit platesassembled against said one face of said stack, said circuit plateshaving means therein providing interconnecting passages between selectedones of said ports, means for fastening said stack and said platestogether, means for supplying fluid to said conduit and means forconnecting fluid input signals to and for receiv ing output fluidsignals from said plates.

2. Apparatus as defined in claim 1 each said element including ventingpassages separate from said input and output passages connected to achosen face of said element and thus to a chosen face of said stack.

3. Apparatus as defined in claim 2 said chosen face being different fromsaid first mentioned face.

4. Apparatus as defined in claim 3 comprising manifold means connectingsaid venting ports.

5. Apparatus as defined in claim 1 including gasket means separatingeach of said circuit plates, holes defined in said circuit plates, holesdefined in said gasket means for connecting said circuit plates inalignment with said plate holes, and passages defined in said plates forinterconnecting chosen ones of said holes.

6. Apparatus as defined in claim 1 including means adjacent said circuitplates for receiving output fluid therefrom, fluidic operated mechanicalmeans receiving said output, and means connecting an electrical switchto said fluidic operated means for providing an electrical output fromsaid unit.

7. Apparatus as defined in claim 1, including fluidic booster means inat least one of said elements and comprising a passage connecting saidfluid supply conduit and the output of said one element independently offluidic connection through said element.

8. Apparatus as defined in claim 1, including fluidic booster means forat least one of said elements and comprising a passage in at least oneof said plates for leading booster fluid from a supply fluid source tosaid element.

9. Apparatus as defined in claim 1 said elements being provided inwafers and at least one element in each said wafer.

10. Apparatus as defined in claim 9 each of said wafers including areceptive pocket defined therein for receipt of a discrete fluidicelement device, passages defined in said wafer for connection toPassages in each said device, and sealing means in said stack orpreventing fluidic flow In any one of said

